Tuesday, August 3, 2010


Over the past week we have been a little busy. Firstly we finished making the mouldings for the dolly, took the hull off the jig, laminated the inside, began fitting internal ribs.
We made the dolly last year after undertaking a basic TIG welding course at TAFE one night a week for a semester. As our final project we made the dolly for the cherub using 60x40x3 6061-T6 aluminium and used 25x1.5mm 316 stainless steel for the axles. All up in materials i think it cost about $200 plus $40 for wheels from eBay. So to fit it to the new boat all we needed to do was make a support for the hull. Note: The reason we used such heavy section aluminium was because of the way our boat sits on our 8x4 ft box trailer.

The above image is the centreboard case as it came out of the vacuum bag as you can see it pulled into the corners quite nicely and the overall finish is pretty good. The second image is the Styrofoam beginning to be melted out with acetone, after beginning this i realised it would have been a much better idea to leave to foam in there until it was in the hull as it is quite flimsy, so i stopped. Although i did notice that acetone was able to seep from the inside to the outside of the skin even though there was 4 layers of 200gsm glass, so it looks like i will need to paint the outside with a coat of resin to help make it water tight after it is in the boat.

I thought this image was worth adding this is the size of the extra reinforcing patch i used under the mast this was 1 200gsm carbon cloth on the 0/90 degree angle to the centre line (compared the the main hull skin at -+45)

I thought this was a good image to add showing the laminate wrapping around the hull/chine. Overall i was pretty happy with how the -+45 laminate laid over the hull and continued to stay approximately at -+45 as we worked towards the bow. I guess I'll see how good that decision was when we come to trying to fair the hull.

The first image is the jig again once once the hull was removed, the second showing how it was able to flat pack and store easily (to dismantle the jig only took 15mins and a electric screw driver)

This image is of the legs of the table/jig, i thought it was worth mentioning how we levelled the jig. Because our jig design had a table with 5 legs it was important to have the leg length adjustable to account for the un-even floor of the garage and our assembly etc. So we used a "coach- screw" in the bottom of each leg allowing the height to be adjusted simply with an open ended spanner.

This is the hull as it can off the jig.

This is the hull after we laminated the inside of the hull, same lay-up as the outside as it is very important to try and keep the laminated balanced so that when the hull is loaded up it doesn't try to warp. Also the floor ribs have been trimmed and ready to glue in and the centreboard case has been roughly fitted.

These are foils after we sanded the recess on the leading edges ready for their joining tape (1x 200gsm layer at -+ 45 to the centre line so it drapes well over the corner the fibres are at the right angle to resist the shear loads at the join)

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